Quote Originally Posted by Sammac View Post
When I bought my Argyle jacket I ordered a 48R, they didn't have a 48S, so when I got it, had the sleeves shortened and the waist pulled in a bit for a better fit, by the way, my suitcoat from Penney's is a 46S.
Part of the problem (if it is a problem) is that a suit jacket is cut entirely different than a kilt jacket-- which can account for the kilt jacket being a full size larger than the suit jacket. Britons also tend to have a physically different "shape" than their North American counterparts, and this, too, can mean that suit/jacket sizes can go up a notch between North America and the UK.

The bottom line is this: No matter how certain you are as to the size of your jacket, you should always "try before you buy".